SIZING BACKER-ROD: Select a backer-rod diameter that is approximately 25% larger than the width of the joint.Joint Width Recommended Diameter3/16" - 1/4" 3/8"3/8" - 1/2" 5/8"1/2" - 3/4" 7/8"3/4" - 7/8" 1-1/8"7/8" - 1-1/4" 1-1/2"1-1/4" - 1-1/2" 2"2" - 2-1/2" 3"2-1/2" - 3-1/4" 4"APPLYING BACKER ROD:
1. Joint fillers have three major functions: Controls depth of the sealant in proper relation to joint width; Provides backing against which the sealant
is applied, forcing the sealant to the sides of the joint; Prevents 3-sided bonding, ensuring proper function of sealant2. To install, compress backer-rod into the joint
before sealants are applied. Joint or opening should be clean and dry and free of obstructions. Install backer-rod using a blunt probe or a plain faced roller to force the rod to the desired depth.3. Compress to a depth of about 1/2 of the width measured at the crown of the backer rod.
4. A template or roller gauge may be used to
control the depth at which the rod is placed.5. Don't stretch, puncture or tear backer-rod during installation but gently force into the joint so that the backer-rod fits tight against the sides of the joint.

PRIMING:1. Follow suggestions for joint-sealant application as directed by sealant manufacturer.
2. Where priming of the joint is necessary, primer
should be applied only to the joint surfaces and
allowed to dry before Backer-Rod is placed. DO
NOT prime Backer-RodQuestions?Email us at sales@bestmaterials.com orCall us at 1-800-474-7570 or 602-272-8128You'll get a prompt reply! similar product terms: backer rod, soft celled backer rod, chinking, chink backing, caulk backing, sealant backing, sealant support, caulk support, soft cell foam, closed cell foam rod, log home chinking